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United States Patent | 5,195,083 |
Imanaka ,   et al. | March 16, 1993 |
A disc-shaped recording medium is used in a recording/reproducing apparatus in which a light beam is arranged to scan along a groove formed as a concentrical or spiral recording track, to record or reproduce data. Additional data which has preeviously been recorded on the disc-shaped recording medium in the shape of irregularities, such as address data indicating each recording track, is previously recorded within the groove in the shape of substantially sinusoidal irregularities of an amplitude which is smaller than the depth of the groove. Thus, if new data is recorded over the additional data, it is possible to easily separate the additional data and the newly-recorded data from each other during reproduction, so that the recording density can be improved.
Inventors: | Imanaka; Ryoichi (Hirakata, JP); Kagata; Akira (Neyagawa, JP) |
Assignee: | Matsushita Electric Industrial Co., Ltd. (Osaka, JP) |
Appl. No.: | 708929 |
Filed: | February 7, 1985 |
PCT Filed: | June 5, 1984 |
PCT NO: | PCT/JP84/00288 |
371 Date: | February 7, 1985 |
102(e) Date: | February 7, 1985 |
PCT PUB.NO.: | WO84/04992 |
PCT PUB. Date: | December 20, 1984 |
Jun 07, 1983[JP] | 58-102068 |
Current U.S. Class: | 369/275.4; 369/16; 369/18; 369/44.13; 369/275.1; 369/275.3 |
Intern'l Class: | G11B 007/24; G11B 007/007 |
Field of Search: | 369/275.1-275.5,284,16,17,18,44,46,32,33 346/135.1,76 L |
2047860 | Jul., 1936 | Boer | 369/17. |
3569636 | Mar., 1971 | Schuller | 369/16. |
3662363 | May., 1972 | Chertok | 369/33. |
3737589 | Jun., 1973 | Redlich et al. | 369/17. |
3860766 | Jan., 1975 | Mori | 369/17. |
3952146 | Apr., 1976 | Plows et al. | 369/16. |
3992593 | Nov., 1976 | Heine | 369/18. |
4310916 | Jan., 1982 | Dil | 369/275. |
4569038 | Feb., 1986 | Nagashima et al. | 369/44. |
Foreign Patent Documents | |||
1125180 | Jun., 1982 | CA. |
John Eargle, "Sound Recording", 1980, p. 311. Laming et al., Optical Storage of Data on a Magnetic Medium, IBM Tech. Disc. Bulletin, vol. 23, No. 7B, p. 3319, Dec. 1980. Dil et al., "Control of Pit Geometry on Video Disks", applied optics, vol. 18, No. 18, Sep. 15, 1979, pp. 3198-3202. Okimo et al., "Developments in Fabrication of Optical Disks", SPIE, vol. 329, Optical Disk Technology )1982) pp. 236-241. |